1. Field of the Invention
The present invention relates to a nozzle surface cleaning apparatus and an image recording apparatus, and more particularly, to a nozzle surface cleaning apparatus which wipes a nozzle surface by abutting and pressing a traveling wiping member against the nozzle surface, and to an image recording apparatus.
2. Description of the Related Art
With use, foreign matter of various types, such as ink residue, paper dust, or the like, adheres to the nozzle surface of an inkjet head which is used in an image recording apparatus, for example, an inkjet recording apparatus. If foreign matter adheres to the nozzle surface, ink droplets ejected from the nozzles are affected, variation occurs in the ejection direction of the ink droplets, it becomes difficult to deposit the ink droplets at the prescribed positions on the recording medium, and this becomes a cause of decline in the image quality. Therefore, in an inkjet recording apparatus, it is important to remove foreign matter periodically by means of a maintenance method, such as wiping, or the like.
For example, Japanese Patent Application Publication No. 2004-195908 describes controlling a wiping sheet which wipes a droplet ejection head, by a winding motor which forms a conveyance mechanism, and wiping the droplet ejection head with the wiping sheet after supplying cleaning liquid to the wiping sheet by a cleaning liquid ejection head. Furthermore, Japanese Patent Application Publication No. 2010-188707 describes a cleaning apparatus having a cleaning liquid supply device which supplies cleaning liquid by a non-contact method onto a nozzle surface of a droplet ejection head, and a wiping device which wipes a nozzle surface.
However, the cleaning apparatus which is described in Japanese Patent Application Publication No. 2004-195908 has a short contact time between the cleaning liquid and the adhering material on the ejection surface of the droplet ejection head, and therefore has not been able to display sufficient cleaning effects by the cleaning liquid. Therefore, it has been necessary to use physical force to remove the adhering material, by applying a high pressure to the droplet ejection head or increasing the relative speed differential between the droplet ejection head and the wiping sheet. However, if excessive force is applied to the ejection surface of a droplet ejection head, then there is a problem in that decline in the properties of the lyophobic film formed on the ejection surface becomes greater.
Moreover, the method of depositing cleaning liquid onto the nozzle surface of the liquid ejection head described in Japanese Patent Application Publication No. 2010-188707 induces ink to be drawn out from the nozzles due to contact with the meniscus in the nozzles, when the nozzle surface is wiped with a wiping member. For instance, if a rubber blade made or silicone, or the like, is used for the wiping member, then drawing out of ink from the nozzles is observed when the relative speed differential becomes large. Moreover, if cloth having fine fibers is used as a wiping member in order to improve the wiping properties, then the drawing out of ink becomes greater due to the absorption characteristics of the wiping member. The ink which is drawn out dries and solidifies, and is pushed inside the nozzle orifices during the next wiping action, thus creating an adverse effect on the directionality of the ejection.